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| author |  Christophe Leroy <christophe.leroy@csgroup.eu>
| 2021-03-23 15:47:59 +0000 |
|---|---|---|
| committer |  Michael Ellerman <mpe@ellerman.id.au>
| 2021-04-03 21:22:21 +1100 |
| commit | b0b3b2c78ec075cec4721986a95abbbac8c3da4f (patch) | |
| tree | e7fc69dcd5cc6fa92e54efa1b93b4272119da67c | |
| parent | powerpc/bpf: Reallocate BPF registers to volatile registers when possible on ... (diff) | |
| download | linux-b0b3b2c78ec075cec4721986a95abbbac8c3da4f.tar.gz linux-b0b3b2c78ec075cec4721986a95abbbac8c3da4f.tar.bz2 linux-b0b3b2c78ec075cec4721986a95abbbac8c3da4f.zip | |
powerpc: Switch to relative jump labels
Convert powerpc to relative jump labels.
Before the patch, pseries_defconfig vmlinux.o has:
9074 __jump_table 0003f2a0 0000000000000000 0000000000000000 01321fa8 2**0
With the patch, the same config gets:
9074 __jump_table 0002a0e0 0000000000000000 0000000000000000 01321fb4 2**0
Size is 258720 without the patch, 172256 with the patch.
That's a 33% size reduction.
Largely copied from commit c296146c058c ("arm64/kernel: jump_label:
Switch to relative references")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/828348da7868eda953ce023994404dfc49603b64.1616514473.git.christophe.leroy@csgroup.eu
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/jump_label.h | 21 | ||||
| -rw-r--r-- | arch/powerpc/kernel/jump_label.c | 4 |
3 files changed, 9 insertions, 17 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 316ab0bf8112..048e2b2a5c63 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -184,6 +184,7 @@ config PPC select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU select HAVE_ARCH_JUMP_LABEL + select HAVE_ARCH_JUMP_LABEL_RELATIVE select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KGDB diff --git a/arch/powerpc/include/asm/jump_label.h b/arch/powerpc/include/asm/jump_label.h index 09297ec9fa52..2d5c6bec2b4f 100644 --- a/arch/powerpc/include/asm/jump_label.h +++ b/arch/powerpc/include/asm/jump_label.h @@ -20,7 +20,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran asm_volatile_goto("1:\n\t" "nop # arch_static_branch\n\t" ".pushsection __jump_table, \"aw\"\n\t" - JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" + ".long 1b - ., %l[l_yes] - .\n\t" + JUMP_ENTRY_TYPE "%c0 - .\n\t" ".popsection \n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -34,7 +35,8 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool asm_volatile_goto("1:\n\t" "b %l[l_yes] # arch_static_branch_jump\n\t" ".pushsection __jump_table, \"aw\"\n\t" - JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t" + ".long 1b - ., %l[l_yes] - .\n\t" + JUMP_ENTRY_TYPE "%c0 - .\n\t" ".popsection \n\t" : : "i" (&((char *)key)[branch]) : : l_yes); @@ -43,23 +45,12 @@ l_yes: return true; } -#ifdef CONFIG_PPC64 -typedef u64 jump_label_t; -#else -typedef u32 jump_label_t; -#endif - -struct jump_entry { - jump_label_t code; - jump_label_t target; - jump_label_t key; -}; - #else #define ARCH_STATIC_BRANCH(LABEL, KEY) \ 1098: nop; \ .pushsection __jump_table, "aw"; \ - FTR_ENTRY_LONG 1098b, LABEL, KEY; \ + .long 1098b - ., LABEL - .; \ + FTR_ENTRY_LONG KEY; \ .popsection #endif diff --git a/arch/powerpc/kernel/jump_label.c b/arch/powerpc/kernel/jump_label.c index 144858027fa3..ce87dc5ea23c 100644 --- a/arch/powerpc/kernel/jump_label.c +++ b/arch/powerpc/kernel/jump_label.c @@ -11,10 +11,10 @@ void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) { - struct ppc_inst *addr = (struct ppc_inst *)(unsigned long)entry->code; + struct ppc_inst *addr = (struct ppc_inst *)jump_entry_code(entry); if (type == JUMP_LABEL_JMP) - patch_branch(addr, entry->target, 0); + patch_branch(addr, jump_entry_target(entry), 0); else patch_instruction(addr, ppc_inst(PPC_INST_NOP)); } |